Abstract: According to uneven illumination distribution in plant cultivation， the light distribution model and illumination uniformity model of LED plant light source array with alternating distribution of the red and blue LEDs were established. Taking LJZWD plant light source array as an example， the light distribution and the change of illumination uniformity were investigated by the means of numerical simulation. The results demonstrated that it could obtain better illumination uniformity when lighting installation height was 143 cm than others， and the illumination uniformity could reach more than 09 if the lighting area decreased to 81% of the light source arrays. It has a guiding significance for the installation of the light source and the selection of plant cultivation area.

Key words: plant light source, LED array, illumination distribution, illumination uniformity